Title :
Cu bump interconnections in 20 μm pitch utilizing electroless tin-cap on 3D stacked LSI
Author :
Tomita, Yoshihiro ; Tago, Masamoto ; Nemoto, Yoshihiko ; Takahashi, Kenji
Author_Institution :
Tsukuba Res. Center, Tsukuba Center Inc., Ibaraki, Japan
Abstract :
The electroless tin-plating on copper has preferable characteristics for thermal compression bonding, although it is easy to decrease in thickness by heating at bonding because of diffusion into the copper. Therefore, the bonding temperature profile was determined to have lower preheating to evaluate the bondabilities with the copper-bumps in 20 μm pitch dressed thin tin-caps on each bump. As a result, the possibilities of the interconnections in 20 μm pitch were confirmed. The bonding temperature was 300°C and the bonding force was 24.5 N. Then, the tin-cap on through-hole electrode (T-COTE) was performed with electroless plating and the basic bonding condition was evaluated on the vertical interconnections. The results showed a sufficient joint between the Cu electrodes through the Si die and the adjacent copper bumps on the interposer. Finally, the results of the feasibilities on the micro-joint at 150°C will be discussed in this paper
Keywords :
copper; electroless deposited coatings; electroless deposition; integrated circuit interconnections; integrated circuit manufacture; integrated circuit metallisation; integrated circuit packaging; tin; 150 C; 20 micron; 300 C; 3D stacked LSI; Cu; Cu bump interconnections; Si; Si die; Sn; Sn plating; T-COTE; bondability; bonding conditions; bonding force; bonding temperature profile; copper interconnects; copper-bumps; dressed thin tin-caps; electroless plated tin-caps; fine pitch; interposer; micro-joint; plating diffusion; plating thickness; preheating; silicon die; thermal compression bonding; through-hole electrode; vertical interconnections; Copper; Electronics packaging; Image analysis; Large scale integration; Pareto analysis; Scanning electron microscopy; Tin; Transmission electron microscopy; X-ray diffraction; X-ray scattering;
Conference_Titel :
Electronic Materials and Packaging, 2001. EMAP 2001. Advances in
Conference_Location :
Jeju Island
Print_ISBN :
0-7803-7157-7
DOI :
10.1109/EMAP.2001.983968
